The wall surrounding the pen from which a tiger escaped – killing a teen and mauling his two pals – is almost four feet shorter than the recommended standard, the San Francisco Zoo’s director admitted yesterday.

The disclosure by zoo chief Manuel Mollinedo came as cops revealed they found a footprint on a fence in front of the wall and were trying to find out whether the victims taunted the beast by dangling their legs over the wall.

Speaking two days after Tatiana, a 350-pound Siberian tiger, went on a bloody rampage, Mollinedo said the wall that surrounds the pen is 12.5 feet high.

That is 3.9 feet less than the 16.4 feet recommended by The Association of Zoos & Aquariums, which accredits the nation’s zoos.

But Mollinedo said AZA safety inspectors examined the 67-year-old wall three years ago and didn’t raise red flags.

“They never noted that as a deficiency,” he said. “Obviously, now that something’s happened, we’re going to be revisiting the actual height.”

Zoo officials said previously that the wall was 13.5, 14, 18 or 20 feet high. Mollinedo said his staff measured it yesterday, and it was just 12.5 feet.

A former zoo employee who spoke on condition of anonymity told The Post a tiger taunted by visitors could jump that high – and, in fact, could jump 16 feet.

The ex-employee said the tigers like to go into the moat because it is warmer and they can hide if they are being taunted.

Teasing of animals is a big problem at the zoo, the former worker said, adding, “I used to spend half my day telling kids not to taunt the animals.”

The ex-employee said there were fewer workers at the zoo to prevent the taunting because staffing was light on Christmas Day, when Tatiana attacked.

The San Francisco Chronicle reported yesterday that the victims might have provoked the attack by dangling their legs over the wall.

A shoe was also discovered in the pen, the newspaper said.

City Police Chief Heather Fong denied a shoe was found, but said a footprint was discovered on the fence.

“We have all three pairs of shoes from the victims, and now we will see if any of them matches the footprint,” she said.

The dead teen was Carlos Sousa Jr. of San Jose. The survivors were identified as his friends Paul and Kulbir Dhaliwal, brothers 19 and 23, who also live in San Jose.

Relatives of the brothers declined to comment.

A San Jose police spokesman said the brothers were arrested outside their home last September and charged with public intoxication and resisting arrest after attempting to fight two other men.

Fong said the tiger first attacked one of the brothers, then fatally slashed Sousa in the throat.

The brothers, leaving a trail of blood, ran 300 yards to the zoo’s Terrace Cafe, where they had eaten earlier, Fong said.

The tiger followed the scent of blood to the cafe, where she attacked the other brother, she said.

Cops tried to distract the big cat with their flashlights and shot her when she moved toward them.